The present invention relates to novel bound materials.
The present invention also relates to novel bound fabrics and thermoplastic materials, and to the methods of constructing and binding them.
The present invention relates to novel bound and structurally reinforced thermoplastic-fabric composite construction materials, which may be decorative or nondecorative, and are readily moldable.
The problem of mating rigid and semi-rigid structural and decorative textile components, such that products capable of being further machine processed result, spans several different technical fields. Essentially, production of structurally sound textiles comprising fibers, yarns and fabrics with appropriate finishes for further molding has been a long standing problem. As such, attempts have been made in which layers of fibers have been combined with an assortment of other structural elements to form the needed composite construction material. For example, the manufacture of composite construction materials comprising reinforcing fibers of filament enclosed in matrices of thermosetting polymers suffer from storage problems because of their finite shelf lives. Thermosetting polymers also harden permanently once heated, precluding further molding of the composite construction materials produced therefrom.
In contrast, thermoplastic resin systems do not have storage problems, since they have high molecular weights and are additionally thermoformable, so that they can be worked many times after their initial molding at temperature.
However, there are difficulties in producing a composite construction material which comprises reinforcing fibers within a matrix of thermoplastic resin. One route of manufacture entails impregnating the reinforcing fibers with a solution of the thermoplastic resin system in a suitable solvent. The solvent is evaporated, and molding is performed to provide the resulting composite construction material. Composite construction materials manufactured by such a method suffer from several major disadvantages. For instance, it is very difficult to completely evaporate the solvent. Some trapping of solvent may occur, resulting in a somewhat porous composite construction material. Porosity reduces strength and may lead to accelerated thermal degradation at elevated temperatures. Another disadvantage is that it is not usually possible to accurately monitor the amount of thermoplastic resin system impregnated into the filaments. Some usually runs off of the filaments resulting in a final thermoplastic resin system content less than anticipated.
An additional disadvantage of known products of the manufacture of composite construction materials has been well documented. When composite construction materials comprising layers of fabric are reinforced with thermoplastic resin system, much dead, or inert, space is often created within the composite. These spaces reduce the value of the composite material produced. These problems are often a function of the methods utilized to bind together component parts of the composite construction material.
In order to overcome the difficulty involved in joining layers of fabric and the necessary thermoplastic reinforcement layers, a systematic combination of fabric layers, thermoplastic resin system, and other needed layers, is required, such that the components of resulting composite construction materials are readily joinable. In so doing, the methods used to bind these composite construction materials, must not adversely effect the properties sought in their creation.
Various materials have previously been used as liners for automotive interiors, but there is an increasing demand for liner materials which can be further machined, preformed, molded, and readily installed, which already have appropriate decorative, structural and molding properties.
While the manufacture of internal furnishing materials for vehicles, houses and the like can be accomplished by subjecting a sheet of plastic to heat and forming solid structures having various curved surfaces, the formed construction material of a plastic sheet alone, has defects such as a flat appearance and a cold and hard feel. To remedy this defect, methods of binding pieces of cloth onto the surfaces of the plastic sheets alone have been adopted. However, due to the insufficiencies in textural stretching of the cloth or in elongation of the fiber or the yarn which constitutes the cloth, it is necessary to cut and sew the cloth according to the pattern beforehand, and then bind the cloth and the plastic sheet together, in order to bind the cloth sufficiently along the resulting curved surface. Not only are these steps disadvantageous in the process, but also the appearance of the finished composite construction material formed has low commercial value.
In order to improve appearance and structure, attempts have been made to bind the cloth and the plastic sheet, and then produce integrated formed products. However, such processes have problems in requiring excessive pressure and temperature for forming, which causes deformation to the resulting composite construction material. These defects result from the large deformation stress and the small thermoplastic property of the cloth under the forming conditions. When heat is exerted at a sufficient temperature to enable the cloth to be subjected to heat forming, the cloth is molded under pressure, and changes its fiber form and recovering property. This results in extreme alteration of appearance and structure, and low decorative or finished value.
Alternate methods of composite construction material manufacture, often generate as many operating constraints as they eliminate, and the prior art is replete with attempts to acquire specific properties in thermoplastic composite construction materials, through creative manipulation and substitution of their component materials. When both structural and decorative properties are sought, it is often appropriate to employ methods of plastics fabrication in combination with mechanical alterations. Intermediate plastic forms have been efficiently used for these purposes.
The present invention is designed to provide bound and structurally reinforced thermoplastic-fabric composite construction materials, that are moldable. They may be produced in a one-pass process using binding means, and may have decorative or other nondecorative elements, as well.
The materials produced by the present invention, overcome the problems in conventional practice, by disposing a series of fabric layers containing structural reinforcement fibers, about a thermoplastic resin system, introduced as powder, film, or yarn, which is combined by binding means employing stitch yarns, which will not melt during heating and molding.
The resulting bound and structurally reinforced thermoplastic-fabric composite construction materials, are moldable, and demonstrate a structural uniformity and homogeneity, heretofore undisclosed in the art. This material is then suitable for further ready molding, and/or pre-forming, to yield a structurally reinforced thermoplastic-fabric composite construction material product. This product is then further moldable, even in its decorative form. An alternate preferred embodiment of the present invention employs stitch yarns which melt, or transform, during molding to create, a finished product having enhanced decorative appeal.